function reordering
add index names
Proper name handling in induction proofs

When a variable is bound in an proof by induction, its index is
incremented. This will prevent name clashes when we ever allow
nested proofs.
Cleanup
Remove unused code
Use nested proof in inductive proof
Simplifiy validEquationProof

With proper variable handling, prop and goal have to be equal
(and not some shady variant of matching).
Inline validEquationProof
Remove support for long comments
Interface for Env
remove unused code
minimal parser cleanup
Extract base constants from baseFixities
Get rid of "defaultToSchematic"
Add TODO
allow arbitrary proof styles below cases
renaming
Add travis config
Travis: Disable GHC 7.8

GHC 7.8 on Travis uses an old Happy version which makes the build fail.
Tuned pretty printing

No functional change intended.